1: For filters manufactured prior to 1991.
2: Based upon availability.
3: Replaced by Nautilus Plus NSP kits. Kit includes top, tank, and clamp assembly
4: Tank top air relief opening may require additional machining. See instructions
5: For use on filters built before 11-94.
6: For use on filters built after 11-94.
7: For use on filters built before 7-93